Inversiot

#include <iostream>

using namespace std;

int main() {
    long n, k;
    cin >> n >> k;
    long c = 0, m = n;
    long l = 0;
    while (c < k) {
        if (c + m - 1 <= k) {
            m--;
            c += m;
        } else {
            l = k - c + 1;
            c = k;
        }
    }
    for (long i = 1; i <= n; i++) {
        long a;
        if (l > i) a = i + n - m + 1;
        else if (l == i) a = n - m + 1;
        else if (i > m) a = n - i + 1;
        else a = i + n - m;
        cout << a << " ";
    }
    cout << endl;
    return 0;
}

Test 1

Group: 1

Verdict: ACCEPTED

Test 2

Group: 1

Verdict: ACCEPTED

Test 3

Group: 1

Verdict: ACCEPTED

Test 4

Group: 1

Verdict: ACCEPTED

Test 5

Group: 1

Verdict: ACCEPTED

Test 6

Group: 2

Verdict: ACCEPTED

Test 7

Group: 2

Verdict: ACCEPTED

Test 8

Group: 2

Verdict: ACCEPTED

Test 9

Group: 2

Verdict: ACCEPTED

Test 10

Group: 2

Verdict: ACCEPTED

Test 11

Group: 3

Verdict: ACCEPTED

Test 12

Group: 3

Verdict: ACCEPTED

Test 13

Group: 3

Verdict: ACCEPTED

Test 14

Group: 3

Verdict: ACCEPTED

Test 15

Group: 3

Verdict: ACCEPTED